"I suppose so," Colgrave concurs, seeing the sense in Karananak's words. "At least it surely can't hurt to give the place a once-over before we go delving in."
As Karananak takes his first step towards the perimeter sweep he bursts into his swarm form and Eve flies up from where ever she has been perched to give a bit of an aerial overview.
I'm not the one with the 30+ Perception check, but my suggestion would be that we're having a quick look for alternate entry/exit routes, nasty monsters lying in ambush, or signs that anybody else might have been poking around here recently. Also, listening for any sounds coming from within. If there are windows we can have a peep through for additional intel. Plus it'd be good to have a general sense of the place's dimensions and layout, and what state of repair it's in.
Yes additional entrances, and signs of anything that might have moved into the building (tracks/shrines etc.). No need to carefully sneak in the front if the whole back of the lab is a cratered out ruin that's been taken over by an entire tribe of something unpleasant.